Nervous system quiz Flashcards
Motor nerves are e____
efferent: carry messages away from the brain. Connect nervous system to muscles or effector organs to take action.
Sensory nerves are a_______
afferent: bring signals to the brain. Activated by physical stimuli; information about body and external environment
Mixed nerves
Carry both afferent and efferent nerve fibres. All spinal nerves are mixed.
axons
thin fibers that neurons use to send electrochemical waves to excite, inhibit, or modulate a cell.
Central neurons
make all input and output connections with other neurons forming neural circuits to create a whole sensory perception
glial cells
provide structural and metabolic support for neurons
peripheral nervous system PNS
sensory neurons from stimulus receptors that inform the CNS, and motor neurons from the CNS to the muscles and organs - EFFECTORS, that take taction.
central nervous system (CND)
Spinal cord and the brain; processes information recieved and signals out appropriate responses to the environment.
ganglia
groups of nerve cell bodies outside of the CNS
autonomic nervous system
responsible for monitoring conditions in internal environment and regulation. Contraction of smooth and cardiac muscle control. Largely involuntary and self regulating.
sympathetic nervous system
Fight or flight mechanisms. Increases heart rate, delivers more blood and oxygen, and slows other organ functions.
preganglionic sympathetic neurons
acetylcholine ACh neurotransmitter. Arise from spinal cord and pass into sympathetic ganglia parallel to cord.
postganglionic neurons
noradrenaline/norepinephrine neurotransmitter. action on glands or muscles is excitatory or inhibitory; raises bp, stimulates heartbeat, dilates trachea and bronchi, shunts blood away from skin and viscera, etc.
parasympathetic nervous system
Returns body functions to baseline after a sympathetic stimulation. Main nerves are the 10th cranial nerves; VAGUS originating in medulla oblongata.
